#include "stdio_impl.h"

/* stdout.c will override this if linked */
static FILE *volatile dummy = 0;
weak_alias(dummy, __stdout_used);
weak_alias(dummy, __stderr_used);

int fflush(FILE *f)
{
    if (!f) {
        int r = 0;
        if (__stdout_used) r |= fflush(__stdout_used);
        if (__stderr_used) r |= fflush(__stderr_used);

        for (f=*__ofl_lock(); f; f=f->next) {
            FLOCK(f);
            if (f->wpos != f->wbase) r |= fflush(f);
            FUNLOCK(f);
        }
        __ofl_unlock();

        return r;
    }

    FLOCK(f);

    /* If writing, flush output */
    if (f->wpos != f->wbase) {
        f->write(f, 0, 0);
        if (!f->wpos) {
            FUNLOCK(f);
            return EOF;
        }
    }

    /* If reading, sync position, per POSIX */
    if (f->rpos != f->rend) f->seek(f, f->rpos-f->rend, SEEK_CUR);

    /* Clear read and write modes */
    f->wpos = f->wbase = f->wend = 0;
    f->rpos = f->rend = 0;

    FUNLOCK(f);
    return 0;
}

weak_alias(fflush, fflush_unlocked);
